<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Symbol</title>
</head>
<body>
    <script>
        // let s1=Symbol("king");
        // let s2=Symbol("king");
        // console.log(s1);
        // console.log(s2);
        // console.log(typeof s2);
        // console.log(s1==s2);
        // console.log(Symbol("king").toString()); //
        // console.log(!Symbol("king")); //false
        // console.log(Number(Symbol("king")));//Uncaught TypeError: Cannot convert a Symbol value to a number
    
        // function add([a,b]){
        //     return a+b
        // }
        // console.log(add([10,20]));

        var map=new Map();
        let i=10;
        map.set(i,'aaaa');
        let o={name:"ton"}
    </script>
</body>
</html>